Screening for Colorectal (Bowel) Cancer

What is colorectal cancer?

Colorectal cancer is a cancer of the colon or rectum. The most common symptoms of colorectal cancer are bleeding from the rectum (back passage), alteration in your bowel habit (for example having prolonged episodes of diarrhoea) and anaemia which can lead to tiredness. (See separate leaflet called 'Cancer of the Bowel' for more details.)

What is colorectal cancer screening?

Screening means looking for early signs of a particular disease in otherwise healthy people who do not have any symptoms and when treatment is likely to be curative. Colorectal cancer screening aims to detect colorectal cancer at an early stage when there is a good chance that treatment will cure the cancer.

Is colorectal cancer screening effective?

As the colorectal cancer screening programme has only recently been introduced, it is too early to know exactly how effective it will be. However, one study has shown that around 2,500 lives could be saved every year in the UK by 2025 due to colorectal cancer screening.

Also, figures published in 2009 from the National Cancer Intelligence Network showed that people with colorectal cancer who are diagnosed at an early stage (stage A) have more than a 9 in 10 chance of surviving the disease. At present, only about 1 in 7 people with colorectal cancer are diagnosed at stage A as the disease does not often cause symptoms at this early stage. At present, most cases of colorectal cancer are diagnosed when the disease is more advanced and causing symptoms. The disease is much less likely to be cured at these later stages.

So, these figures show just how important it is to diagnose the disease as early as possible for the best chance of a cure. This is exactly what colorectal cancer screening is all about - to diagnose the condition early to give the best chance of a cure.

Who is invited for colorectal cancer screening?

As colorectal cancer is much more common in older people, the decision has been made for people of a certain age to be invited to participate in the colorectal cancer screening programme. This involves testing three samples of your faeces (stools or motions) for blood. The NHS Bowel Cancer Screening Programme has been introduced in the UK as follows:

• In England, people aged 60 to 69 will be routinely offered screening every two years. If you are aged 70 or over and screening has started in your area, you can phone the helpline on 0800 707 60 60 to request the kit, if you would like to have screening. From 2010, screening will be extended to cover people up to age 75 as standard.
• In Scotland, people aged 50 to 74 will be offered screening every two years.
• In Wales, people aged 60 to 69 will be offered screening every two years. From 2010, the screening programme will be extended to cover people aged up to 74. By 2015 it will be open to everyone who lives in Wales between the ages of 50 and 74.
• In Northern Ireland, the age range for screening is still to be confirmed.

If you are in the relevant age groups then you will automatically be sent an invitation, then your faecal occult blood (FOB) screening kit, so you can do the test at home. After your first screening test, you will then be sent another invitation and screening kit every two years until you reach the maximum age. You can then request further kits if you would like to continue to be included in the screening programme.

What does the screening kit involve?

As blood in the faeces is common in people with colorectal cancer, the kit involves testing the faeces (stools or motions) for occult (hidden) blood. This is also called faecal occult blood testing (FOB).

The testing kit is a very simple way for you to collect small samples of your faeces in your own home. Although it sounds embarrassing and unpleasant, it is surprisingly easy and quick to actually do. There are clear instructions sent with the kit. You obtain a sample by using a small scraper to scrape some faeces off toilet tissue which you have just used after going to the toilet. You will then need to wipe very small samples of three different bowel motions on a special card, which you then send in a hygienically sealed, prepaid envelope to a laboratory for testing. You will be sent the results of your test by post within two weeks.

Although the FOB test can confirm the presence of blood, it is unable to show where the blood is coming from or what the cause of the blood is. Colorectal cancer is just one cause of blood in faeces.

What are the results of the screening kit?

The results of the FOB test can be either:

• Negative. That is, no blood present. This is the result for around 98 out of 100 of people. Routine screening will then be offered to you two years later. No further tests are needed.
• Unclear. This is the result for around two out of 100 people. The FOB test then needs repeating.
• Positive. That is, blood is found to be present. This is the result for around two out of 100 people. You will then be referred for further investigation which is usually a colonoscopy. A colonoscopy is a test in which a long, thin, flexible telescope (a colonoscope) is passed through your rectum into your colon (large bowel) in order for the whole of your colon and rectum to be looked at in detail.

There are various reasons other than colorectal cancer for having a positive test. For example, some medical conditions including haemorrhoids (piles) can lead to a positive test.

Colorectal cancer screening can also detect polyps (growths) on the inner lining of the bowel. These are not cancers, but may develop into cancers over time. They can easily be removed, which reduces the risk of colorectal cancer developing.

Following a colonoscopy after screening, about five in 10 people who have a colonoscopy will have a normal result, about four in 10 will be found to have a polyp, which if removed may prevent cancer developing and about one in 10 people will be found to have cancer.

Note: a normal test result does not completely rule out colorectal cancer. It is therefore important to be aware of the symptoms of bowel cancer and see your doctor if you are concerned.

Other reasons for screening

Some people have a particularly high risk of developing colorectal cancer. They are offered regular screening tests, usually in the form of a colonoscopy or specialised scans:

People with a family history of colorectal cancer

Some people have an increased risk of colorectal cancer if they have close relatives who have developed colorectal cancer. This risk is given as detailed below as it varies between families. The recommendations for further investigations in the different groups may vary throughout the country. You should talk with your own doctor if you have members of your family who have had colorectal cancer.

High risk
High risk people are those with certain inherited conditions, which include familial adenomatous polyposis (FAP), hereditary non-polyposis colorectal cancer (HNPCC), and some other syndromes including Peutz-Jegher's syndrome and juvenile polyposis syndrome. These conditions are very rare.

Relatives of patients with FAP are offered investigations every year from age 13-15 years until age 30, and 3-5 yearly thereafter until age 60. Relatives of patients with HNPCC are usually advised to have regular bowel screening from the age of 25, or five years earlier than the age their youngest affected relative developed colorectal cancer.

High-moderate risk
People who have a three or more first-degree relatives (mother, father, brother, sister, child) who have had colorectal cancer, should be offered five yearly colonoscopy from age 55 until 75 years.

Moderate risk
People with only one first-degree relative affected by colorectal cancer aged under 45 years or with only two first degree relatives who have had colorectal cancer have a moderate risk of developing colorectal cancer. These people should be offered a single colonoscopy at age 55 years. If the investigation is normal, then no further investigations (other than the normal bowel cancer screening by FOB) are recommended.

Low risk
People with family histories that are different to those listed above are classified as low risk. These people do not need any further investigations (other than the normal bowel cancer screening by FOB).

People with inflammatory bowel disease

People with ulcerative colitis and Crohn's disease have a higher risk than normal of developing colorectal cancer. It is therefore usually recommended that if you have one of these conditions, then you have further tests to screen for colorectal cancer. Your specialist will usually inform you of the timing of any future tests as this can vary between people.

Further help and information

The NHS Bowel Cancer Screening Programme

England - Helpline: 0800 707 6060 Web: www.cancerscreening.nhs.uk/bowel/index.html
Scotland - Helpline: 0800 012 1833 Web: www.bowelscreening.scot.nhs.uk
Wales - Helpline: 0800 294 3370 Web: www.wales.nhs.uk/sites3/home.cfm?orgid=747
Northern Ireland - watch out for news at www.cancerni.net

Department of Health

Have information leaflets called Bowel Cancer Screening - the facts and Bowel cancer screening the colonoscopy investigation - available in many different languages.
Find them by searching on their website for 'bowel cancer screening' - www.dh.gov.uk

Beating Bowel Cancer

39 Crown Road, St. Margarets,Twickenham, TW1 3EJ
Tel (helpline): 08450 719 301 Web: www.beatingbowelcancer.org
Aims include to raise awareness of symptoms and promote early diagnosis of bowel cancer.

Bowel Cancer UK

7 Rickett Street, London, SW6 1RU
Tel: 08708 50 60 50 (Bowel Cancer Advisory Service) Web: www.bowelcanceruk.org.uk
A charity dedicated to raising awareness of bowel cancer, improving the quality of life of those affected by the disease and, ultimately, reducing deaths from this disease.

Bowel Cancer Wales

Sherwood, Llandraw Woods, Maesycoed, Pontypridd R.C.T, CF37 1EX
Tel: 01443 408813 Web: www.bowelcancerwales.com
Aims to raise awareness of the disease and raise funds to research bowel cancer in Wales